This invention relates generally to keyboards for use in conjunction with small computers and other electronic devices, and more particularly to a flexible keyboard which is characterized by the dimensions of a conventional keyboard during use and which is adapted to be rolled and/or folded into a compact configuration for transportation and storage.
Ongoing miniaturization has characterized the entire developmental history of computing machines. Thus, early vacuum tube-type computers filled entire rooms and required dedicated air conditioning systems to perform rudimentary mathematical functions. The introduction of discrete component transistors was accompanied by size reductions and significant increases in computing power as was the subsequent introduction of the integrated circuit. More recently the introduction of chips comprising many thousands of transistors has facilitated the introduction of powerful computers small enough to be carried in the pocket or purse.
As the size of computers has been reduced, the size of the associated displays and keyboards has also been reduced. Modern palm-top computers, mini laptop computers, personal digital assistants, etc., hereinafter referred to collectively as xe2x80x9csmall computers,xe2x80x9d often have keyboards so small as to require the use of a stylus for their operation. Many computer owners find the use of miniature keyboards to be inconvenient and would prefer a keyboard similar in size to a conventional keyboard for document preparation, data input, and similar tasks. However, the size and weight of a conventional keyboard exceed that of a small computer, such that the two are seldom used in combination.
The present invention comprises a flexible membrane keyboard which overcomes the foregoing and other difficulties long since associated with the use of small computers. In accordance with the broader aspects of the invention, there is provided a flexible membrane keyboard having dimensions and key arrangements the same as or similar to a conventional keyboard. The keyboard is light in weight and is adapted to be rolled and/or folded into a compact size to facilitate transportation and storage.
In accordance with more specific aspects of the invention, the keyboard comprises opposed flexible plastic membranes secured in engagement with one another. Pressure sensitive switches are embedded between the flexible plastic membranes and comprise keys of the keyboard. Outputs from the pressure sensitive switches are directed to a microprocessor which in turn directs an output from the keyboard to a computer or similar device.